Fortuitous Discovery of Asymptomatic Homozygous Antithrombin Deficiency: A Rare p.Leu131Phe Heparin-Binding Site Mutation: A Case Report.
4 affiliations
- 1Department of Hematology Laboratory CHU Brugmann Université Libre de Bruxelles (ULB) Brussels Belgium.
- 2Hemato-Oncology Unit Hôpital Universitaire des Enfants Reine Fabiola Hôpitaux Universitaires de Bruxelles (HUB) Brussels Belgium.
- 3Department of Hematology Laboratory Cliniques Saint-Pierre Ottignies Belgium.
- 4Department of Haematology Universitair Ziekenhuis Brussel (UZ Brussel) Vrije Universiteit Brussel (VUB) Brussels Belgium.
Abstract
Homozygous Type II heparin-binding site antithrombin deficiency is a rare inherited thrombophilia associated with a high risk of early thrombotic events. We report a 6-week-old infant homozygous for the SERPINC1 c.391C>T (p.Leu131Phe) variant (Antithrombin Budapest III), with markedly reduced antithrombin activity (12%). Despite this high-risk genotype, the patient remains asymptomatic without thrombotic or vascular abnormalities and has not required anticoagulant treatment to date. This case highlights the phenotypic heterogeneity of homozygous antithrombin Budapest III deficiency and the importance of genetic diagnosis, family screening, and careful long-term follow-up. Trial Registration: The authors have confirmed clinical trial registration is not needed for this submission.
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BibTeX
@article{cherkaoui2026fortuitous,
title = {{Fortuitous Discovery of Asymptomatic Homozygous Antithrombin Deficiency: A Rare p.Leu131Phe Heparin-Binding Site Mutation: A Case Report.}},
author = {Sara Cherkaoui and Laurence Dedeken and Anne Demulder and Joanna Simar and Christelle Orlando and Laurence Rozen},
journal = {EJHaem},
year = {2026},
month = nov,
doi = {10.1002/jha2.70398},
url = {https://europepmc.org/article/MED/42999715},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Fortuitous Discovery of Asymptomatic Homozygous Antithrombin Deficiency: A Rare p.Leu131Phe Heparin-Binding Site Mutation: A Case Report.
AU - Sara Cherkaoui
AU - Laurence Dedeken
AU - Anne Demulder
AU - Joanna Simar
AU - Christelle Orlando
AU - Laurence Rozen
PY - 2026
DA - 2026/11/07
JO - EJHaem
DO - 10.1002/jha2.70398
UR - https://europepmc.org/article/MED/42999715
AB - Homozygous Type II heparin-binding site antithrombin deficiency is a rare inherited thrombophilia associated with a high risk of early thrombotic events. We report a 6-week-old infant homozygous for the SERPINC1 c.391C>T (p.Leu131Phe) variant (Antithrombin Budapest III), with markedly reduced antithrombin activity (12%). Despite this high-risk genotype, the patient remains asymptomatic without thrombotic or vascular abnormalities and has not required anticoagulant treatment to date. This case highlights the phenotypic heterogeneity of homozygous antithrombin Budapest III deficiency and the importance of genetic diagnosis, family screening, and careful long-term follow-up. Trial Registration: The authors have confirmed clinical trial registration is not needed for this submission.
SN - 2688-6146
ER -